Shelter



FIG. 1 is a perspective view of a shelter showing my new design;

FIG. 2 is a magnified top view of the area marked in FIG. 1;

FIG. 3 is a front view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines depict environmental subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a shelter, as shown and described. 